Index: kernel/db/cat_tag_processor.php
===================================================================
--- kernel/db/cat_tag_processor.php	(revision 14476)
+++ kernel/db/cat_tag_processor.php	(working copy)
@@ -89,12 +89,12 @@
 				$params['pass'] = 'm,'.$this->Prefix;
 			}
 
-			$item_id = isset($params[$id_prefix.'_id']) && $params[$id_prefix.'_id'];
-			if (!$item_id) {
-				$item_id = $this->Application->GetVar($this->getPrefixSpecial().'_id');
-				if (!$item_id) {
-					$item_id = $this->Application->GetVar($this->Prefix.'_id');
-				}
+			// set by PrintList2 tag
+			$item_id = $this->Application->GetVar($this->getPrefixSpecial() . '_id');
+
+			if ( !$item_id && ($this->Special != 'next' && $this->Special != 'previous') ) {
+				// set from page url
+				$item_id = $this->Application->GetVar($this->Prefix . '_id');
 			}
 
 			$object =& $this->getObject($params);
Index: kernel/db/db_event_handler.php
===================================================================
--- kernel/db/db_event_handler.php	(revision 14476)
+++ kernel/db/db_event_handler.php	(working copy)
@@ -221,6 +221,16 @@
 				$event->setEventParam('raise_warnings', 1);
 			}
 
+			if ( $event->Special == 'previous' || $event->Special == 'next' ) {
+				$object =& $this->Application->recallObject( $event->getEventParam('item') );
+				/* @var $object kDBItem */
+
+				$list_helper =& $this->Application->recallObject('ListHelper');
+				/* @var $list_helper ListHelper */
+
+				return $list_helper->getNavigationResource($object, $event->getEventParam('list'), $event->Special == 'next');
+			}
+
 			if (preg_match('/^auto-(.*)/', $event->Special, $regs) && $this->Application->prefixRegistred($regs[1])) {
 				// <inp2:lang.auto-phrase_Field name="DateFormat"/> - returns field DateFormat value from language (LanguageId is extracted from current phrase object)
 				$main_object =& $this->Application->recallObject($regs[1]);
@@ -1011,6 +1021,9 @@
 					$this->Application->ConfigValue($sorting_configs['DefaultSorting1Field']) => $this->Application->ConfigValue($sorting_configs['DefaultSorting1Dir']),
 					$this->Application->ConfigValue($sorting_configs['DefaultSorting2Field']) => $this->Application->ConfigValue($sorting_configs['DefaultSorting2Dir']),
 				);
+
+				// TODO: lowercase configuration variable values in db, instead of here
+				$list_sortings[$sorting_prefix]['Sorting'] = array_map('strtolower', $list_sortings[$sorting_prefix]['Sorting']);
 			}
 
 			// use default if not specified in session
Index: kernel/db/db_tag_processor.php
===================================================================
--- kernel/db/db_tag_processor.php	(revision 14476)
+++ kernel/db/db_tag_processor.php	(working copy)
@@ -606,6 +606,42 @@
 	}
 
 	/**
+	 * Returns ID of previous record (related to current) in list.
+	 * Use only on item detail pages.
+	 *
+	 * @param Array $params
+	 * @return int
+	 */
+	function PreviousResource($params)
+	{
+		$object =& $this->getObject($params);
+		/* @var $object kDBItem */
+
+		$list_helper =& $this->Application->recallObject('ListHelper');
+		/* @var $list_helper ListHelper */
+
+		return $list_helper->getNavigationResource($object, $params['list'], false);
+	}
+
+	/**
+	 * Returns ID of next record (related to current) in list.
+	 * Use only on item detail pages.
+	 *
+	 * @param Array $params
+	 * @return int
+	 */
+	function NextResource($params)
+	{
+		$object =& $this->getObject($params);
+		/* @var $object kDBItem */
+
+		$list_helper =& $this->Application->recallObject('ListHelper');
+		/* @var $list_helper ListHelper */
+
+		return $list_helper->getNavigationResource($object, $params['list'], true);
+	}
+
+	/**
 	 * Allows to modify block params & current list record before PrintList parses record
 	 *
 	 * @param kDBList $object
Index: units/helpers/list_helper.php
===================================================================
--- units/helpers/list_helper.php	(revision 14476)
+++ units/helpers/list_helper.php	(working copy)
@@ -122,4 +122,79 @@
 			}
 			return $user_sorting_start;
 		}
+
+		/**
+		 * Returns ID of previous/next record related to current record
+		 *
+		 * @param kDBItem $object
+		 * @param string $list_prefix
+		 * @param bool $next
+		 * @return int
+		 */
+		function getNavigationResource(&$object, $list_prefix, $next = true, $select_fields = null)
+		{
+			$list =& $this->Application->recallObject($list_prefix);
+			/* @var $list kDBList */
+
+			if (!isset($select_fields)) {
+				$select_fields = '%1$s.' . $object->IDField;
+			}
+
+			if (is_array($select_fields)) {
+				$select_fields = implode(', ', $select_fields);
+			}
+
+			$list->SelectClause = str_replace(Array ('%1$s.*', '%2$s'), Array ($select_fields, ''), $list->SelectClause);
+
+			$operators = Array (
+				'asc' => $next ? '>' : '<',
+				'desc' => $next ? '<' : '>',
+			);
+
+			$where_clause = Array ();
+			$order_fields_backup = $list->OrderFields;
+			$lang = $this->Application->GetVar('m_lang');
+
+			foreach ($list->OrderFields as $index => $order) {
+				$where_clause[$index] = Array ();
+
+				if (!$next) {
+					$list->OrderFields[$index][1] = $order_fields_backup[$index][1] == 'asc' ? 'desc' : 'asc';
+				}
+
+				for ($i = 0; $i <= $index; $i++) {
+					$order_field = $order_fields_backup[$i][0];
+					$is_expression = $order_fields_backup[$i][2];
+
+					if ( preg_match('/^IF\(COALESCE\(.*?\.(l' . $lang . '_.*?), ""\),/', $order_field, $regs) ) {
+						// undo result of kDBList::getMLSortField method
+						$order_field = $regs[1];
+						$is_expression = false;
+					}
+
+					$order_direction = $order_fields_backup[$i][1];
+
+					$field_prefix = array_key_exists($order_field, $list->VirtualFields) || $is_expression ? '' : '%1$s.';
+
+					$actual_operator =  $i == $index ? $operators[$order_direction] : '=';
+					$where_clause[$index][] = $field_prefix . $order_field . ' ' . $actual_operator . ' ' . $this->Conn->qstr( $object->GetDBField($order_field) );
+				}
+
+				$where_clause[$index] = '(' . implode(') AND (', $where_clause[$index]) . ')';
+			}
+
+			$where_clause = '(%1$s.' . $object->IDField . ' != ' . $object->GetID() . ') AND ((' . implode(') OR (', $where_clause) . '))';
+			$list->addFilter('navigation_filter', $where_clause);
+
+			$sql = $list->extractCalculatedFields( $list->GetSelectSQL() );
+
+			$list->removeFilter('navigation_filter');
+			$list->OrderFields = $order_fields_backup;
+
+			if ( $this->Application->isDebugMode() ) {
+				$this->Application->Debugger->appendHTML('Quering <strong>' . ($next ? 'next' : 'previous') . '</strong> item for "<strong>' . $list_prefix . '</strong>" list:');
+			}
+
+			return $this->Conn->GetOne($sql);
+		}
 	}
\ No newline at end of file